A medical device holding assembly (50) includes a carrier sheath (52) which carries an endoluminal medical device such as an embolization coil (10). The assembly also includes a housing (54) including at least one holding element (56) to hold the sheath (52), and a fixation device (80) attached to the housing (54) and coupled to the sheath (52). The fixation device (80) includes a locking element (120) having an unlocked configuration which allows the sheath (52) to slide relative to the housing (54) and a locked configuration which fixes the sheath (52) to the housing (54). A lock actuator (90) is configured to lock permanently the locking element (120) into the locked configuration. As a result, the sheath (52) with the medical device (10) held therewithin cannot be removed from the holding assembly (50) during the deployment procedure, thereby ensuring that the procedure can be carried out by a single person and also protecting the integrity of the medical device (10) before it is deployed into a patient.
